Characteristics
1. Shape and volume
2. Compressibility
3. Rigidity/Fluidity
4. Energy
5. Density
6. Diffusion
Solid
1. They have a definite shape as well as definite volume.
2. Solids are completely incompressible.
3. Solids possess rigidity.
4. Their particles have minimum energy.
5. They have high density.
6. They normally do not show the property of diffusion although some rare examples of diffusion of one solid into another are known.
Liquid
1. They have a definite volume but no definite shape.
2. Liquids are almost incompressible.
3. Liquids can flow, therefore they possess fluidity which is lower than that of gases
4. Their particles have energy higher than those of solids.
5. Their density is lower than those of solids but much higher than those of gases.
6. They show the property of diffusion. As a result, solids, liquids and gases all can diffuse into liquids.
Gas
1. They have neither a definite shape nor a definite volume.
2. Gases are highly compressible.
3. Gases flow more easily than liquids and thus have the highest fluidity.
4. Their particles have highest energy.
5. They generally have very low densities.
6. They diffuse very rapidly. The rate of diffusion of a gas is, however, inversely proportional to the square root of its density. Thus, lighter 7. gas diffuses more rapidly than the heavier one.